The present invention relates generally to aircraft gas turbine engines, and, more specifically, to aircraft mounts therefor.
A gas turbine engine may be mounted to an aircraft at various locations such as the wings, fuselage, or tail by a corresponding structural pylon. The engine is typically mounted at both its forward and aft ends by corresponding mounts for carrying various loads to the aircraft through the pylon. These loads include vertical loads such as the weight of the engine itself; axial loads due to the thrust generated by the engine; side loads such as those due to wind buffeting; and roll loads or torques in three planes. The mounts must also accommodate both axial and radial thermal expansion and contraction of the engine relative to the supporting pylon.
The mounts are typically effective for carrying in-plane loads to the pylon which are those loads occurring in a single axial plane extending radially outwardly from the longitudinal or centerline axis of the engine. These loads include vertical and horizontal components, as well as rotary torque or moments.
Typically, one engine mount is provided for carrying the axial directed thrust load from the engine to the pylon which are usually tension loads during forward propulsion of the aircraft, and compression loads during thrust reverse braking of the aircraft upon landing.
In one exemplary aft engine mount which attaches the engine to the side of an aircraft fuselage, a mounting pin extends laterally outwardly from the fuselage pylon and engages a spherical bearing housing attached to the engine. The various in-plane and thrust loads are carried to the pin using single loadpath connections. The mount must therefore be designed as a monolithic structure which is over-designed to provide extra strength for increasing the safety margin for avoiding failure. The mount does not include other failsafe features which would provide alternate loadpaths in the event of a failure of any component in the primary loadpath between the engine and the pylon. The single loadpath mount is therefore larger and heavier than typical failsafe engine mounts, which increases cost and reduces aircraft efficiency in view of the additional weight.
Accordingly, a low-weight, failsafe engine mount is desired for attaching the gas turbine engine to the aircraft.